Accompanying monocytopenia and low or absent NK cells shall even raise more suspicion about GATA2 deficiency syndrome, ATXPC and MIRAGE syndromes, but this should not be a prerequisite for genetic testing because many patients with ATXPC and MIRAGE have “reverted” the GOF mutation resulting in a recovery of cell numbers in the PB. The gene discussed is GATA2; the disease is MIRAGE syndrome.